Sea to Summit Reactor Extreme Sleeping Bag Liner, Standard

2026-02-21T19:00:00

My son doesn't usually do winter camping but this year he had to. We bought this liner for making sleeping bar warmer and it served the purpose well. Thanks!

Kautilya V.

Originally posted at

2026-02-05T19:00:00

I had an old one of these that had seen hundreds of nights of use and was getting worn. I liked that this one had a hood which could retain a pillow. It's a must on cold nights with a quilt and feels like it adds 10-15 degrees to my sleeping warmth. If you're a cold sleeper or use a quilt this is a great buy.

Bryan T.

Originally posted at

2026-02-04T19:00:00

I just summited Aconcagua. they require a -20°F bag, but wind chills exceeded -37°F. I got this liner for an extra layer of protection and it worked wonderfully. frost would build around the edge of the sleeping bag but I would be warm inside. 5/5*

Zach P.

Originally posted at

2026-01-30T19:00:00

Wow, what difference this makes to increase you bag rating. Used in on Kilimanjaro in and out of my bag and stayed nice and toasty without needing to buy a sub zero sleeping bag!

Andrea H.

Originally posted at

2026-01-22T19:00:00

I bought this for a trip up Mt Kilimanjaro and it was such a great purchase! It added a great deal of warmth, I like the way the fabric feels against my skin, and the ability to still walk around wearing it or keep it on when getting out of the tent to go to the bathroom is amazing!

Kayla K.

Originally posted at

2026-01-20T19:00:00

First test of the liner was a doozy - 13 degrees. But it worked like a champ and gave me that extra warmth to peacefully sleep during the night on the Sheltowee Trace.

Kevin M.

Originally posted at

2026-01-14T19:00:00

Warm and cozy. Fits well. You get what you pay for so watch for a sale and buy quality.

Mary P.

Originally posted at

2026-01-04T19:00:00

Used this liner coupled with my Spark Sleeping bag and was toasty! Loved having a "blanket" option for inside and outside of my sleeping bag. Was soft and cozy and really made my sleep system versatile.

Nicole S.

Originally posted at

2026-01-04T19:00:00

This liner kept me very warm on my recent coastal backpacking trip. There was a point where I got a little too warm and moved it bunched up to the side and it was noticeably warmer than the rest of my bag! Highly recommend if you need some extra warmth on a trip.

KC A.

Originally posted at

2026-01-02T19:00:00

This liner is an excellent value for the price. I purchased it on sale for around $50, and it has been very firm and effective at keeping me warm, even in cold temperatures.

Avi D.

Originally posted at

2025-12-11T19:00:00

Seems to add about 10 degrees of comfort.

Ian K.

Originally posted at

2025-07-05T20:00:00

Used the bag liner for a week camping. Worked great. Definitely recommend your Sleeping Bag Liners. Very roomy.

Glenda C.

Originally posted at

2025-05-21T20:00:00

I have a down quilt was getting cold drafts coming in and disrupting my sleep. I actually put the quilt inside the liner and I was super warm

John A.

Originally posted at

2025-04-22T20:00:00

Compact. Easy to deploy. Adds loads of warmth for a small footprint. This is a great, inexpensive option to add significant warmth and extend the temperature range of your sleep system. If you're camping in multiple temp ranges, this can allow you to use a lighter weight bag and then use the liner on cold nights. Sea to summit makes awesome kit, this is no exception.

Frostbite

Originally posted at

2025-03-08T19:00:00

The mummy shape is very comfortable, and the materials feel high-quality.

Dorit h.

Originally posted at

2025-03-08T19:00:00

Soft and comfy

ANTHONY S.

Originally posted at

2025-02-13T19:00:00

I was on an upper Grand Canyon river trip during the polar vortex in January, and purchased this liner in anticipation of that, since I only have a 20 degree sleeping bag. This liner did its job and kept me perfectly warm and cozy during the trip!! With the caveat that I also had a puffy blanket; if I hadn't, the liner may not have been quiiite warm enough (it got down to 10 degrees at night, according to my friend who brought a thermometer on the trip). But regardless, I would highly recommend it for cold weather camping! I also really liked the snap-closure arm holes, so I could have my arms free instead of them being mummified in the liner.

Heidi S.

Originally posted at

2024-11-11T19:00:00

This was a great addition to my Spark Ultralight sleeping bag to give me a bit of an insulation boost for a cooler weather backpacking trip. For my purpose, this was a much better option vs. buying a warmer sleeping bag. My only complaint is the opening at the bottom. Seriously, who needs that? I certainly have no interest in walking around camp in my sleeping bag liner. There are better ways to keep warm when not in my tent. The opening with the drawcord just adds unnecessary weight, cost and an opening for a draft. Drop the opening, sew it closed and it will be perfect.

Joe Z.

Originally posted at

2024-10-28T20:00:00

When temps get low, this liner is great to take the edge off of the cold air. Comfortable fabric. I am pleased with the results. Partner to a zero degree bag, it is exactly what I was looking for

Benjamin A.

Originally posted at

2024-10-10T20:00:00

This liner is always with me, if I am not using to stay extra toasty in my bag, I use it as a pad sheet for sleeping on during the hot desert nights. Absolute must have for any serious outdoors person

Alex C.

Originally posted at

2024-09-30T20:00:00

Just went on a 3 days camping trip using my traverse IIv -4 sleeping bag and this liner inside. I am always cold, but this liner really warmed up the bag and made it toasty. Waking up to -3 celsius in the morning, I didn't want to get up because it was so nice inside my bag, liner and tent. For me, I will get down booties though as my feet are never warm. Highly recommended and it is light and packs small.

Angela S.

Originally posted at

2024-08-15T20:00:00

Light weight and amazing warmth. I ordered this to add the additional warmth and my bag and it has exceeded my expectations!

Andrea D.

Originally posted at

2024-08-10T20:00:00

Reactor sleeping bag liners are a must have, not only to protect the sleeping bag but to give added comfort and warmth. The reactor extreme really delivers and its design features, with the arm holes and base draw cord, make it functionally versatile and adaptable over a range of temperatures.

William P.

Originally posted at

2024-07-25T20:00:00

Staying toasty on cold nights is critical for a good night sleep for me. The opening at the bottom allows me to have my feet out and still benefit from the extra warmth.

Laura P.

Originally posted at

2024-04-30T20:00:00

Love that it's easy to pack, light and super warm. The texture is super soft too. Highly recommend as an extra layer for your sleeping bag! Perfect for super cold camping nights.

Jachunter

Originally posted at

2024-04-26T20:00:00

I received this product free, complimentary of influenster, in exchange for an honest review. Super high quality and warm LINER! Better than most actual sleeping bags and only a liner! This has motivated me to purchase a sleeping bag by Summit because of how nice and warm the liner is.

Tkeegz

Originally posted at

2024-04-24T20:00:00

Material is soft and durable, easy to bring along on a camping trip. Fits snug in the little bag it comes in. Its like laying in a soft comforting cocoon, I cant wait to use it when I go camping. Its breath-able and yet keeps you warm at the same time.

Zoejanereviews

Originally posted at

2024-04-22T20:00:00

Went camping up at Yellowstone national park and this baby arrived in the mail just in time. While my friends were shivering at night and feeling the chill, I was toasty and warm. Also this was super easy just to clip into my pack and didn't have to be a hassle to bring with. Great device and I loved every minute of using it

Andy B.

Originally posted at

2024-04-17T20:00:00

Truly impressed with the quality of this liner; perfect for campers and outdoor enthusiasts alike. Super lightweight but also relatively warm, so it'd make a great addition to your camping supplies. Could probably double as a sleeping bag in the summer! Overall, I definitely recommend.

Amandac1137

Originally posted at

2024-04-15T20:00:00

This sleeping bag liner packs up very small and is convenient to carry around. It is very lightweight and breathable but the material feels high quality. I didn't have any issue washing it. On its own it is not very warm, which is actually preferable here in a warmer climate, but it would definitely help to insulate in combination with a sleeping bag.

Marcyl7

Originally posted at